Repeated pneumococcal infections can occur in immunocompromised patients although sporadic cases have been reported in immunocompetent patients. During the period June 1, 1992 to January 31, 1997 we treated 439 patients with pneumococcal infections. All pneumococcal strains were isolated from sterile body sites. Thirteen of these patients (3%) had more than one episode (twelve patients had two episodes and one patient had three). Repeated episodes occured as follows: 1) one (6%) among 16 patients with sickle cell anemia or other hemoglobinopathies 2)five (21%) among 24 HIV-infected children and 3)seven(2%) among the rest 399 patients. None of these 7 patients had an underlying disease and immunologic evaluation was within normal limits. The outcome of the patients with repeated episodes did not differ from that of the others. MICs of penicillin were determined in all strains isolated from patients with repeated episodes. All but one were penicillin susceptible. Twelve sets of isolates were available for serotyping and genotyping by pulse-field gel electrophoresis. Eight of the 12 sets, including two recovered within four weeks after the first episode, revealed that there were of different origin. In three pairs isolates were indistinguishable and in one pair the strains were closely related. The negative cultures after the first episode and the mean time between the first and second episode (6-11 weeks) in three of these four patients suggest that the patients re-acquired the strain from their close environment. We conclude that repeated pneumococcal infections are more common among immunocompromised and particularly in HIV patients; however, their occurence in healthy children is not uncommon.